1. Field of the Invention
The present invention relates to a box and to an insert for a box, each made up of at least two elements. The elements are made of molded plastic material and hinged to each other via at least one hinge mechanism. In the case of a box, the two elements can be identified as the bottom of the box and the cover of the box.
The features of the present invention is specifically designed for a flat box that is to receive a magnetic or optical medium for high density recording, and more specifically, for a compact disc (i.e., a digital audio disc). The invention is useful with other types of boxes, capable of containing various types of articles.
2. Description of Prior Art
Conventional boxes for storing items such as compact discs essentially comprise two elements, namely a bottom and a cover, which are hinged to each other about a hinge mechanism. Both elements are made of rigid transparent plastic material that is generally injected-molded such as, for example, clear polystyrene.
One of the elements carries two lateral studs which engage in openings provided in the other element, thus forming a pair of stub axles in axial alignment to make up the hinge. A paper label is generally inserted inside each box element and can be seen from the outside because each of the elements is transparent. The label has information concerning the contents of the box. Generally, the cover element label is slid over the inside face of the cover wall and is held therein by lateral tab members. The label is sometimes replaced by, or associated with, a removable booklet. The disc is held in place in a molded tray of plastic material that is clipped in the bottom element, with the label being sandwiched between the tray and the bottom wall. The intermediate tray includes a central disc-retaining member made up of radially-deformable resilient fingers which engage the disc in the central opening of the disc. This retaining member is commonly referred to as a xe2x80x9crosettexe2x80x9d or a xe2x80x9cthimblexe2x80x9d. Generally, the bottom label has two marginal flaps folded over at right angles that are placed against the inside faces of the sides of the bottom element. Information is provided on these folded-over flaps to be visible through the sides of the box when the box is stored in such a manner so as to allow the edge to be visible. Some of the disadvantages of the above-described box are that it is difficult and time consuming to manufacture and is relatively expensive. The three elements making it up, i.e., the bottom, cover, and intermediate tray, are manufactured separately by an injection-molding process, and they are subsequently assembled together. In addition to the assembly operation, there is the operation of putting the labels into place. Another drawback of know boxes is the fragility of the lugs carrying the lateral studs constituting the hinge, and giving rise to many rejects on the assembly line and breakages during use.
Great Britain Patent No. 2,185,710 describes a box made by injection molding talc-filled polypropylene. The box is provided with a label formed by a sheet, also made of polypropylene, which is integrated in the box by overmolding during the injection process. The bottom and the cover of that box are formed as a single piece. Furthermore, the bottom and cover are connected together by a hinge-forming zone that is weak. The polypropylene sheet covers the hinge zone in order to provide it with mechanical reinforcement and thus increase its strength characteristics. In this device, the label does not constitute the hinge, and it does not replace the hinge; it merely serves to reinforce it. A major disadvantage of this type of device is that the material forming the box needs to be a non-breaking flexible material since it needs to act as a hinge and must therefore withstand repeated flexing without breaking or cracking.
A primary object of the present invention is to eliminate the various disadvantages outlined above with regard to the prior art structures by presenting a box structure which, while still being competitive in price, and relatively simple to manufacture, has a hinge that is particularly robust, long-lasting and able to withstand repeated flexing without breaking or cracking.
Another object of the present invention is to make it possible to be able to use rigid and brittle materials, in particular clear polystyrene which has remarkable qualities of transparency in the type of box structure as described herein.
Still another object of the present invention is to provide a box, in particular a flat box for storing a compact disc, in which the disc is held in place without requiring the use of an intermediate tray, but is held directly in the bottom element of the box. In this respect, it should be observed that with conventional boxes, the presence of the label in the bottom element makes it impossible to mold the rosette directly into the bottom wall.
Still an additional object of the present invention is to provide a novel system for holding and supporting a disc in a box; inside the bottom element of the box; the box itself system making it easy to install and remove the disc.
Still an additional object of the present invention is to improve the legibility of information visible on the side of a box used for storing a disc.
The various objects of the present invention described above are achieved by the fact that the box or box element in accordance with the present invention includes a flexible sheet of synthetic material which is fixed to each of the two hinged-together elements that constitute the box by overmolding, the flexible sheet having an intermediate free zone which comprises by itself, the hinge of the box. Thus, since the hinge comprises solely the intermediate free zone, it is sufficient for the material of the sheet to be flexible, and to be capable of mechanically withstanding back-and-forth flexing. The specific nature or composition of the material used for the two box elements is not important. The only critical point is that on overmolding there must be surface adhesion compatibility between the material forming the sheet and materials forming the box elements.
Also, according to various aspects of the present invention:
(i) at least one of the elements possesses a plane main wall, at least one of the faces of which is completely or partially covered by a portion of the flexible sheet;
(ii) the plane main wall has weight-reducing openings that are also covered by the flexible sheet;
(iii) the flexible sheet is an informative label;
(iv) the elements are made of transparent plastic material, such as clear polystyrene;
(v) the flexible sheet is made of a transparent material;
(vi) the label-forming flexible sheet includes information on both faces; and
(vii) the flexible sheet is made of material having good mechanical strength while being compatible on molding with the plastic material forming the elements, the material preferably being, a polypropylene-polystyrene or a polyethylene-polystyrene composite.
When the present invention specifically relates to a box:
(i) one of the two elements is a bottom member and the second element is a cover member, and the two elements have complementary mutually engaging profiles disposed facing each other in an intermediate free zone, suitable for providing mutual guidance for the two elements while the box is being closed, and then for providing relative locking therebetween after closure;
(ii) both the box (bottom) element and the cover element each possesses a main plane wall, one of whose faces is completely or partially covered by a portion of the flexible sheet, and at least one of the main walls including a rim adjacent to the hinge and likewise covered by the sheet;
(iii) the rim is provided with a profile for mutual engagement; and
(iv) the sheet portion covers the rim and carries on its face informative marking visible through the transparent thickness of the rim, which rim is shaped to from a magnifying glass. The sheet can be fixed to the bottom and cover elements either via their outside faces or via their inside faces.
According to other possible characteristics of the box or of the box element:
(i) it is designed to receive at least one recording medium, such as a compact disc;
(ii) at least one of its hinged-together elements is provided with members for centering and retaining the disc; and
(iii) these members for centering and retaining the disc are constituted by a rosette integrally molded with the elements and suitable for engaging in the central hole of the disc.
In one embodiment of the box, the box is flat in shape, rectangular in outline, and has a relatively small thickness. Its bottom element carries the members for centering and retaining the disc held therein.
In an another embodiment, the members for centering and retaining the disk consist of a pair of arms which are suitable for clamping against the outside of the disc and which are integrally molded with the main wall of the bottom element, forming an acute angle therewith, the disc being retained by being clipped between the two arms.
According to other possible characteristics:
(i) the flexible sheet may contain anti-theft detection means;
(ii) one of the hinged-together elements of the box element consists of a tray suitable for supporting and retaining a pair of compact discs, each against a respective one of its two faces, while the other element consists of a support strip, the assembly being dimensioned and shaped in such a manner as to be capable as being inserted inside a box having a shape and dimensions similar to a box designed to receive a single compact disc;
(iii) after being molded, the elements are connected to each other by at least one frangible tab such that they initially form rigid assembly facilitating automatic positioning of discs on the tray, and positioning of the box element in the box; and
(iv) the support strip includes lateral webs provided with projections enabling it to be snap-fastened in the box.
In one embodiment of the present invention an insert for a box for storing and supporting an item such as compact discs comprises at least two injection molded plastic rigid elements. The elements are hinged to each other by a single hinge, the hinge including a flexible sheet fixed to each of the rigid elements by overmolding during injection molding. The hinge is formed by an area of the flexible material, the area being free of the rigid plastic material. One of the elements includes a tray member adapted to support and contain a pair of compact discs, each of the discs lying against each other. Included is a second of the elements adapted to be secured to the box and including a support strip member, wherein the elements are formed of rigid and brittle plastic material and the flexible sheet is formed of a flexible material having good mechanical strength sheet and being compatible in a molding environment with the material forming the elements, whereby the insert is dimensioned and shaped to allow the insert to be inserted within a storage box normally designed to store only a single compact disc.
In another embodiment, an insert for a box comprises a tray suitable for supporting and retaining a pair of compact disks, each against a respective one of the discs two faces, and a support strip, to which said tray is hinged. The insert is dimensioned and shaped to be capable of being inserted inside the box which has a shape and dimensions similar to a standard box designed to receive a singe compact disc. Both the tray and the support strip are constructed of a rigid and brittle material molded by injection molding, and both are hinged to each by an intermediate free zone of a flexible sheet made of a material having good mechanical strength while being compatible during molding with the plastic material forming both the tray and the support strip. The sheet is fixed to the tray and the strip by overmolding in the injection mold, and the support strip further includes lateral webs provided with projections enabling the web to be snap-fastened in the standard box.
In yet another embodiment an insert for a box comprises a tray suitable for supporting and retaining a pair of compact discs, each against a respective one of the discs two faces. Included is a support strip hinged to the tray. The combined tray and support strip is dimensioned and shaped to be adapted to being inserted inside the box having the shape and dimensions similar to a standard box designed to receive a single compact disc. The tray and the support strip are both made of a rigid and brittle injection molded material, and are hinged to each other solely by an intermediate free zone of a flexible sheet made of a material having good mechanical strength while being compatible, during injection molding, with the plastics material forming both the tray and the support strip. The sheet is fixed to the tray and the strip by overmolding during injection molding. At each of two ends of the strip there is positioned a transverse web. Included on the outside of the web is a pair of projections, the first of the projections is adapted to snap into a first corresponding hole for receiving a first stub axle for hinging a cover onto a bottom element of the box, and the second of the projection is adapted to snap into a second corresponding hole provided in a side wall of the bottom element of the box.
Yet another embodiment of the present invention comprises a method for manufacturing an insert, the insert being adapted to retain a pair of compact discs therein, the insert being dimensioned and shaped so that it is capable to be inserted within a standard box initially intended for storing s single disc. The insert is formed of two thermoplastic elements including a first element comprising a strip member adapted to be secured to the box, and a second element comprising a tray member adapted to support a pair of compact discs, one against each of its two faces, the elements being formed of rigid and brittle plastic material and being hinged to each other by a single hinge, the hinge including a flexible thin sheet having mechanical strength and being compatible on molding with the material forming the elements, the flexible thin sheet being fixed to each of the elements by overmolding during injection molding. The hinge is formed by an area of the flexible material which is free of the rigid plastic material, wherein one uses an injection mold comprising two complementary half mold parts. The mold includes a first part and a second part, which may either be brought together in order to close the mold or separated from each other in order to open the mold. The mold defines when closed two adjacent cavities, the first cavity corresponding to the shape of the tray member and the second cavity to the shape of said strip member. The first half mold part is provided with an injection nozzle having a point, the nozzle suitable for introducing hot molten thermoplastic material into the first cavity when the mold is closed. The cavities are separated from each other, when the mold is closed, by a protuberance formed in one of the half mold parts and having substantially a shape with a chamfered linear nose edge which comes very close to a flat area of the other half mold part when the mold is closed, the nose edge being cut by at least a transverse gap situated in the vicinity of the injection nozzle when the mold is closed. The method comprising the following steps: (a) introducing the flexible sheet between the mold parts and positioning the sheet against a flat area, in front of the nose; (b) holding said flexible sheet against the flat area; (c) closing the mold, so that the chamfered linear edge of the nose firmly presses the flexible sheet toward the flat area; (d) injecting molten thermoplastic material into the mold through the injection nozzle so that it simultaneously fills directly the first cavity and via the gap, the second cavity, and covering a side of the flexible sheet without coating the part that is gripped between the chamfered linear edge and the flat area; (e) allowing the injected material to cool and to become stiff; and (f) ejecting the molded insert, the strip member and the tray member while each remain rigidly connected to each other by at least a frangible tab constituted by the material contained in the gap at the end of the molding process, in such manner that the hinging can only occur later, after breaking of the tab when the user pivots the tray member for the first time.